Non-single-crystalline light emitting semiconductor device matrix with insulation

ABSTRACT

A light emitting semiconductor device which is provided with a first non-single-crystal semiconductor layer, a second non-single-crystal semiconductor layer formed on the first semiconductor layer and a third non-single-crystal semiconductor layer formed on the second semiconductor layer, or a first non-single-crystal semiconductor layer, many second non-single-crystal semiconductor layers formed on the first semiconductor layer and a third non-single-crystal semiconductor layer formed on the first semiconductor layer to cover the second semiconductor layers. The first and second semiconductor layers have either one and the other of p and n conductivity types, respectively. Semiconductors of the first, second and third layers are each doped with a dangling bond and recombination center neutralizer. The semiconductor of the second layer has a smaller energy gap than the semiconductors of the first and third layers.

This application is a continuation of Ser. No. 014,184, filed Feb. 11,1987, which itself was a divisional of Ser. No. 742,700, filed Feb. 9,1982, both now abandoned, which itself is a divisional of Ser. No.347,359, filed Feb. 9, 1982 now U.S. Pat. No. 4,527,179 issued Jul. 2,1985.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light emitting semiconductor devicewhich is constituted using semiconductor layers.

2. Description of the Prior Art

Heretofore there has been proposed a light emitting semiconductor deviceof the type that p and n type single crystal semiconductor layers areformed one on the other to define therebetween a pn junction. In thiscase, the single crystal semiconductor layers are usually formed ofdirect gap semiconductors of the III-V compounds, such as GaAs,GaAs_(1-x) P(0<x<1),Ga_(1-x) Al_(x) As(0<x<1) and so forth. The reasonfor using such direct gap III-V compound semiconductors is that theyprovide for enhanced light emission efficiency as compared with indirectgap III-V compound semiconductors. However, the formation of suchsemiconductor layers involves much difficulty as the semiconductorconstituting the layers must be provided in a single crystal form.

Accordingly, the conventional light emitting semiconductor device usingsemiconductor layers of the direct gap III-V compound semiconductors aredifficult and expensive to manufacture.

Furthermore, in the prior art light emitting semiconductor device it iscustomary that the two single-crystal semiconductor layers laminated todefine therebetween the pn junction are formed of direct gapsingle-crystal III-V compound semiconductors of the same composition,i.e. of the same energy gap, and hence the pn junction is ahomojunction.

With such a light emitting semiconductor device, when applying a forwardbias voltage to the pn junction so as to emit light, the barrier heightof the pn junction is decreased, facilitating electrons from the n typesemiconductor layer to diffuse deeply into the p type semiconductorlayer across the pn junction and holes from the p type semiconductorlayer to diffuse deeply into the n type semiconductor layer across thepn junction.

This leads to the shortcoming of impaired light emission efficiency.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a novellight emitting semiconductor device which is free from the abovesaiddefects of the prior art.

According to an aspect of the present invention, the light emittingsemiconductor device comprises using non-single-crystal semiconductorlayers. The non-single-crystal semiconductor layers can easily beobtained because the semiconductor forming them is non-single-crystal,not single crystal.

Therefore, the present invention permits easy fabrication of the lightemitting semiconductor device at low cost.

According to another aspect of the present invention, the light emittingsemiconductor device is provided with a first non-single-crystalsemiconductor layer, a second non-single-crystal semiconductor layerformed thereon and a third non-single-crystal semiconductor layer formedthereon, or a first non-single-crystal semiconductor layer, many secondnon-single-crystal semiconductor layers formed thereon and a thirdnon-single-crystal semiconductor layer formed on the first semiconductorlayer in such a manner that the second semiconductor layers are buriedin the third layer. The first and third semiconductor layersrespectively have either one of p and n conductivity types and the otherso as to form, a pin or pn junction, including the second semiconductorlayers.

In this case, non-single-crystal semiconductors forming the first,second and third semiconductor layers are doped with a dangling bond andrecombination center neutralizer. Hence the non-single-crystalsemiconductors behave as direct gap semiconductors.

The non-single-crystal semiconductor forming the second semiconductorlayer is smaller in energy gap than the non-single-crystalsemiconductors of the first and third semiconductor layers. For thisreason, when applying a bias forward voltage relative to the pin or pnjunction so as to effect light emission, even if the barrier height ofthe pin or pn junction is reduced, at least electrons from the third (orfirst) non-single-crystal semiconductor layer do not easily diffuse intothe first (or third) layer across the junction, or holes from the first(or third) non-single-crystal semiconductor layer do not easily diffuseinto the third (or first) layer across the junction. As a consequence,radiative recombination of the electrons and holes is effectivelydeveloped in the second non-single-crystal semiconductor layer.

Therefore, the present invention is able to offer a light emittingsemiconductor device of high light emission efficiency.

Other objects, features and advantages of the present invention willbecome more fully apparent from the following detailed description takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an enlarged sectional view schematically illustrating a firstembodiment of the light emitting semiconductor device of the presentinvention;

FIG. 2A to 20 schematically show energy band structures explanatory ofthe first embodiment;

FIG. 3 is an enlarged sectional view schematically illustrating a secondembodiment of the present invention;

FIGS. 4A to 40 schematically show energy band structures explanatory ofthe second embodiment;

FIG. 5 is an enlarged sectional view schematically illustrating a thirdembodiment of the present invention;

FIGS. 6A to 60 schematically show energy band structures explanatory ofthe third embodiment;

FIG. 7 is an enlarged sectional view schematically illustrating a fourthembodiment of the present invention;

FIGS. 8A and 8B schematically show energy band structures explanatory ofthe fourth embodiment;

FIGS. 9 and 11 are enlarged sectional views schematically illustratingfifth and sixth embodiments of the present invention, respectively.

FIGS. 10A to 10C and 12A to 12C schematically show energy bandstructures explanatory of the fifth and sixth embodiments, respectively.

FIGS. 13 and 15 are enlarged sectional view schematically illustratingseventh and eighth embodiments of the present invention, respectively.

FIGS. 14A to 14C and 16A to 16C schematically show energy bandstructures explanatory of the seventh and eighth embodiments,respectively.

FIGS. 17 and 19 are enlarged sectional views schematically illustratingninth and tenth embodiments of the present invention, respectively.

FIGS. 18A to 18C and 20A to 20C schematically show energy bandstructures explanatory of the ninth and tenth embodiments, respectively.

FIG. 21 is an enlarged sectional view schematically illustrating aneleventh embodiment of the present invention;

FIG. 22A to 22B schematically shows an energy band structure explanatoryof the eleventh embodiment;

FIG. 23 is an enlarged sectional view schematically illustrating atwelfth embodiment of the present invention;

FIG. 24A to 24B schematically shows an energy band structure explanatoryof the twelfth embodiment;

FIGS. 25 and 26 are enlarged sectional views schematically illustratingthirteenth and fourteenth embodiments of the present invention,respectively.

FIGS. 27, 28, 29 and 30 are enlarged sectional views schematicallyillustrating fifteenth, sixteenth, seventeenth and eighteenthembodiments of the present invention, respectively.

FIGS. 31, 32, 33 and 34 are enlarged sectional views schematicallyillustrating nineteenth, twentieth, twenty-first and twenty-secondembodiments of the present invention, respectively.

FIGS. 35, 36, 37 and 38 are enlarged sectional views schematicallyillustrating twenty-third, twenty-fourth, twenty-fifth and twenty-sixthembodiments of the present invention, respectively.

FIG. 39A is a plan view schematically illustrating a twenty-seventhembodiment of the present invention;

FIGS. 39B and 39C are sectional views taken on the lines B--B and C--Cin FIG. 39A, respectively.

FIG. 40 is a circuit diagram of the device depicted in FIG. 39A;

FIG. 41A is a plan view schematically illustrating a twenty-eighthembodiment of the present invention;

FIGS. 41B and 41C are sectional views taken on the lines B--B and C--Cin FIG. 41A, respectively;

FIG. 42A is a plan view schematically illustrating a twenty-ninthembodiment of the present invention;

FIGS. 42B and 42C are sectional views taken on the lines B--B and C--Cin FIG. 42A, respectively.

FIG. 43A is a plan view schematically illustrating a thirtiethembodiment of the present invention;

FIGS. 43B and 43C are sectional views taken on the lines B--B and C--Cin FIG. 43A, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 schematically illustrates a first embodiment of the lightemitting semiconductor device of the present invention, in which alight-transparent electrode 2 is formed on a light-transparent insulatedsubstrate 1. The insulated substrate 1 may be formed as of glass,ceramic, synthetic resin of the like material. The electrode 2 may beformed as tin oxides, indium oxide, antimony oxide, indium-titaniumoxide, a mixture of antimony oxide and titanium oxide or the like.

On the light-transparent electrode 2, semiconductor layer 3, 4 and 5 areformed one on another in this order:

The semiconductor layers 3, 4 and 5 are each formed of anon-single-crystal semiconductor such as an amorphous, semi-amorphous orpolycrystalline semiconductor. The semi-amorphous semiconductor has sucha structure that its degree of crystallization varies spatially, and itis typically a semiconductor which is composed of a mixture of amicro-crystalline semiconductor having a lattice strain and a particlesize of 5 to 200 Å and a non-single-crystal semiconductor such as anamorphous semiconductor. The non-single-crystal semiconductor, whichforms each of the semiconductor layers 3, 4 and 5, may be the Group IVelement such as silicon (Si) or germanium (Ge), a carbide of the GroupIV element such as silicon carbide (Si_(x) C_(1-x)).0.<x<x) or germaniumcarbide (Ge_(x) C_(1-x)).0.<x<1), a nitride of the Group IV element suchas silicon nitride (Si₃ N_(4-x)).0.<x<4) or germanium nitride (Ge₃N_(4-x) (.0.<x<4), or an oxide of the Group IV element such as siliconoxide (SiO₂₋).0.<x<2).

The non-single-crystal semiconductor forming the layer 3 is doped withthe Group III element which is a p type impurity, such as boron (B),aluminum (Al), or indium (In), to make the layer 3 p-type. Thenon-single-crystal semiconductor forming the layer 5 is doped with theGroup V element which is an n type impurity, such as phosphors (P),arsenic (As), or antimony (Sb), rendering the layer 5 n-type.

The semiconductor layer 4 is composed of a non-single-crystalsemiconductor 14. The non-single-crystal semiconductor forming the layer14 is not doped with any of the abovesaid Group III and IV elements orit is doped with them so that the conductivity type of the layer 14 maybe compensated for, making the layer 14 exhibit the i conductivity type.

The non-single-crystal semiconductors constituting the layers 3, 4 and 5are each doped with a dangling bond and recombination center neutralizersuch as hydrogen or a halogen such as fluorine. In consequence, thenon-single-crystal semiconductor behaves as a direct gap one to generateradiative recombination of carriers.

The non-single-crystal semiconductors for the layers 3, 4 and 5 may bethe aforementioned Group IV element, its carbide, nitride or oxide orits compound semiconductor but the non-single-crystal semiconductor ofthe layer 4 and consequently the layer 14 has a smaller energy gap thandoes the non-single-crystal semiconductors of the layers 3 and 5. Thatis to say, letting the energy gaps of the non-single-crystalsemiconductors of the layers 3, 14 and 5 be represented by Eg₃, Eg₄ andEg₅, respectively, they bear relationships Eg₃ >Eg₁₄, Eg₅ >Eg₁₄ as shownin FIGS. 2A to 2I, Eg₃ ≧Eg₁₄, Eg₅ >Eg₁₄ as shown in FIGS. 2J to 2L,(which illustrate the case of Eg₃ ÷Eg₁₄), Eg₅ ≧Eg₁₄, Eg₅ >Eg₁₄ as shownin FIGS. 2M to 2O (which illustrate the case of Eg₅ ÷Eg₁₄). In the casewhere the energy gaps Eg₃, Eg₁₄ and Eg₅ bear relationships Eg₃ >Eg₁₄,Eg₅ >Eg₁₄, the energy gaps Eg₃ and Eg₅ may bear a relationship Eg₃ =Eg₅as shown in FIGS. 2A, 2F and 2I, Eg₃ >Eg₅ as shown in FIGS. 2B, 2C and2G, or Eg₃ >Eg₅ as shown in FIGS. 2D, 2E and 2H. In order that theenergy gaps Eg₃, Eg₁₄ and Eg₅ of the semiconductors of the layers 3, 14and 5 may bear the abovesaid relationships, these layers 3, 14 and 5 maypreferably be formed of a silicon carbide (Si_(x) C_(1-x)).0.≦x≦1). Inthis case, however, the value of x in the Si_(x) C_(1-x) used for thelayer 14 is selected larger than the value of x in the Si_(x) C_(1-x)for the layers 3 and 5. In such a case, the energy gap Eg₁₄ of thesemiconductor of the layer 14 is obtained in the range of 1.5 to 1.7 eVand the energy gaps Eg₃ and Eg₅ of the semiconductors of the layers 3and are obtained in the range of 2.0 to 4.0 eV.

It is preferred that the semiconductor of the layer 14 be Si_(x)Ge_(1-x) (.0.≦x≦1) and the semiconductors of the layers 3 and 5 Si_(x)C_(1-x) (.0.≦x≦1). In this case, however, the value of x in the Si_(x)Ge_(1-x) is selected larger than the value of x in the Si_(x) C_(1-x).

Further, it is preferable that the semiconductors of the layers 3, 14and 5 be Si_(x) Ge_(1-x) (.0.≦x≦1). In this case, however, the value ofx in the SixGe_(1-x) for the layer 14 is selected larger than the valueof x in the Si_(x) Ge_(1-x) for the layers 3 and 5.

Still further, it is preferable that the semiconductor of the layer 14be Si_(x) C_(1-x) (.0.≦x≦1) and the semiconductors of the layers 3 and 5Si₃ N_(4-x) (.0.≦x≦4).

The non-single-crystal semiconductor layer 3 makes ohmic contact withthe light-transparent electrode 2. The non-single-crystal layer 14defines a pi junction 8 between it and the semiconductor layer 3. Whenthe energy gaps Eg₃ and Eg₁₄ of the non-single-crystal semiconductorsforming the layers 3 and 14 bear the abovesaid relation Eg₃ >Eg₁₄ or Eg₃<Eg₁₄, the pi junction 8 is heterojunction but, in the case of Eg₃=Eg₁₄, it is a homojunction. The non-single-crystal semiconductor layer5 forms an ni junction 9 between it and the semiconductor layer 14. Whenthe energy gaps Eg₁₄ and Eg₅ of the semiconductors forming the layers 14and 5 have the aforesaid relation Eg₁₄ <Eg₅ or Eg₁₄ >Eg₅, the nijunction 9 is a heterojunction and, in the case of Eg₁₄ =Eg₅, it is ahomojunction.

The semiconductor layers 3, 4 and 5 can be obtained very easily by theplasma CVD technique because the semiconductor forming them may benon-single-crystal. The semiconductor layers 3 and 5 are usually formedto a desired thickness exceeding 0.1 μm. The semiconductor layer 14 isusually thinner than the semiconductor layers 3 and 5; it is 100 Å to 2μm thick, in particular, 0.1 to 0.4 μm.

The semiconductor layers 3, 4 and 5 form the pi junction 8 between thelayers 3 and 14 and the ni junction 9 between the layers 14 and 5,constituting a pin junction structure as a whole.

The semiconductor layers 3 and 5 have such impurity concentrations whichprovide such energy band profiles as shown in FIGS. 2A to 20 when aforward bias voltage is applied to the abovesaid pin junction structurein the case where the energy gaps Eg₃, Eg₁₄ and Eg₅ of thesemiconductors forming the semiconductor layers 3, 14 and 5 bear theaforementioned relationships. That is to say, the semiconductor layers 3and 5 have such impurity concentrations that at least an edge of theconduction band C.B. of the semiconductor forming the layer 3 assumes ahigher energy potential position than does the edge of the conductionband C.B. of the semiconductor forming the layer 14, or an edge of thevalence band V.B. of the semiconductor forming the layer 5 assumes ahigher energy potential position than does the edge of the valence bandV.B. of the semiconductor forming the layer 14. In the drawings, thereis shown the case where the edges of the conduction band C.B. of thesemiconductor of the layer 3 and the valence band V.B. of thesemiconductor of the layer 5 are respectively higher than the edges ofthe conduction band C.B. and the valence band V.B. of the semiconductorof the layer 14.

The non-single-crystal semiconductor layer 5 is covered with an opaqueelectrode 6 to make ohmic contact therewith as indicated by 10. Theopaque electrode 6 may be formed of aluminum (Al), nickel (Ni), cobalt(Co), molybdenum (Mo) or the like.

When connecting a bias power source 11 across the electrodes 2 and 6making the former positive relative to the latter, the pin junctionconstituted by the semiconductor layers 3, 14 and 5 is biased in aforward direction. As a result of this, holes 12 from the p typesemiconductor layer tend to flow out therefrom into the n typesemiconductor layer 5 across the pi junction 8, the i type semiconductorlayer 14 and the ni junction 9 as typically depicted in FIGS. 2A, 2D,2G, 2I and 2M. Conversely, electrons 13 from the n type semiconductorlayer 5 also tend to flow into the p type semiconductor layer 3 acrossthe ni junction 9, the i type semiconductor layer 14 and the pi junction8. However, in the case where the edge of the valence band V.B. of thesemiconductor of the layer 5 assumes a higher potential position thandoes the edge of the valence band of the semiconductor forming the layer14, the ni junction 9 constitutes a high barrier against the holes 12.This limits the flowing of the holes 12 into the semiconductor layer 5across the ni junction 9, resulting in increased density of holes in thelayer 14. Where the edge of the conduction band C.B. of thesemiconductor of the layer 3 assumes a higher position than theconduction band C.B. of the semiconductor of the layer 14, the pijunction makes up a high barrier against the electrons 13. This limitsthe flowing of the electrons 13 into the semiconductor layer 3 acrossthe pi junction 8, increasing the density of the electrons 13 in thelayer 14.

As a result of this, direct transition type radiative recombination ofcarriers is effectively developed in the semiconductor layer 14,generating light with high efficiency. The light generated in thesemiconductor layer 14 is emitted to the outside, passing through thesemiconductor layer 3, the transparent electrode 2 and the transparentinsulated substrate 1 as indicated by 15 in FIG. 1. In this case, aportion of the light is directed towards the electrode 6 through thesemiconductor layer 5 but it is reflected by the electrode 6 to beemitted to the outside through the semiconductor layers 5, 4 and 3, thetransparent electrode 2 and the transparent substrate 1 as similarlyindicated by 15. The light 15 thus emitted has a wavelengthcorresponding to the energy gap Eg₁₄ of the semiconductor of the layer14.

FIG. 3 illustrates a second embodiment of the light emittingsemiconductor device of the present invention. The parts correspondingto those in FIG. 1 are identified by the same reference numerals.

The light emitting semiconductor device of this embodiment is identicalin construction with the embodiment of FIG. 1 except that the i typesemiconductor layer 14 forming the non-single crystal semiconductorlayer 4 of the latter is replaced with an n type non-single-crystalsemiconductor layer 24 to form a pn junction between the semiconductorlayers 3 and 24 and an nn junction 29 between the semiconductor layers24 and 5.

The semiconductor layer 24 is formed of the same non-single-crystalsemiconductor as is employed for the semiconductor layer 14 in theembodiment of FIG. 1 and the non-single-crystal semiconductor is dopedwith the dangling bond and recombination center neutralizer as in thecase of FIG. 1. Accordingly, this semiconductor behaves as one thatdevelops direct transition type radiative recombination of carriers.

The non-single-crystal semiconductor, which forms the semiconductorlayer 24, is doped with the same n type impurity as that for thesemiconductor layer 5 of the light emitting semiconductor device shownin FIG. 1, whereby the semiconductor layer 24 is made n-type.

The semiconductor of the semiconductor layer 24 has an energy gap Eg₂₄smaller than the energy gap Eg₃ of the semiconductor layer 3 and/or theenergy gap Eg₅ of the semiconductor of the layer 5 as is the case withthe energy gap Eg₁₄ of the semiconductor of the layer 14 in theembodiment of FIG. 1. Accordingly, when the energy gaps Eg₃ and Eg₂₄ ofthe semiconductors of the layers 3 and 24 bear such a relationship asEg₃ >Eg₂₄ or Eg₃ <Eg₂₄, the pn junction 28 is a heterojunction but, inthe case of Eg₃ =Eg₂₄, it is usually a homojunction. The nn junction 29is a heterojunction when the energy gaps Eg₂₄ and Eg₅ of thesemiconductors of the layers 24 and 5 bear such a relationship as Eg₂₄<Eg₅ or Eg₂₄ >Eg₅ and, in the case of Eg₂₄ =Eg₅, the nn junction 29 isusually homojunction.

The semiconductor layers 3, 24 and 5 have such impurity concentrationsthat when applying a forward bias voltage to the pn junction 28 in thecase where the energy gaps Eg₃, Eg₂₄ and Eg₅ of the semiconductors bearthe abovesaid relationship, the edge of the conduction band C.B. of thesemiconductor of at least the layer 3 assumes a higher position than theedge of the conduction band of the semiconductor of the layer 24, or theedge of the valence band V.B. of the semiconductor of the layer 5assumes a higher position than the edge of the valence band of thesemiconductor of the layer 24. In practice, the semiconductor layer 24has a lower impurity concentration than the semiconductor layers 3 and5.

Connecting across the electrodes 2 and 6 the bias power source 11 whichis forward with respect to the pn junction 28, the holes 12 in the ptype semiconductor layer 3 tend to flow out therefrom into the n typesemiconductor layer 5 across the pn junction 28 and the n typesemiconductor layer 29 as typically shown in FIGS. 4A, 4D, 4J and 4M.Further, the electrons 13 in the semiconductor layer 5 also tend to flowout therefrom into the semiconductor layer 3 across the n typesemiconductor layer 24. In this case, however, at least the pn junction28 serves as a high barrier against the holes 12, or the nn junction 29constitutes a high barrier against the electrons 13. Therefore, thedensity of the holes 12 and/or electrons 13 increases in thesemiconductor layer 24. As a result of this, radiative recombination ofcarriers effectively takes place in the semiconductor layer 24 toefficiently generate light, which is delivered to the outside asindicated by 15. The light thus emitted has a wavelength correspondingto the energy gap Eg₂₄ of the semiconductor of the layer 24.

FIG. 5 illustrates a third embodiment of the light emittingsemiconductor device of the present invention, in which the partscorresponding to those in FIG. 1 are identified by the same referencenumerals.

This embodiment is identical in construction with the embodiment of FIG.1 except that the i type non-single-crystal semiconductor layer 14 ofthe latter is replaced with a p type non-single-crystal semiconductorlayer 34, and that a pp junction 38 and a pn junction 39 are formedbetween the semiconductor layers 3 and 34 and between the semiconductorlayers 34 and 5, respectively.

The semiconductor layer 34 has the same structure as the layer 14 in theembodiment of FIG. 1 except that the former is doped with the same ptype impurity as that used for the semiconductor in the device ofFIG. 1. Accordingly, the semiconductor layers 3, 34 and 5 constitute apn juncstructure, though no further detailed description will be givenof the layer 34. The energy gaps EG₃, Eg₃₄ and Eg₅ of the semiconductorsforming the semiconductor layers 3, 34 and 5 assume such relative valuesand positions as shown in FIGS. 6A to 60.

Connecting across the electrodes 2 and 6 the bias power source 11 whichis formed with respect to the pn junction 39, light is efficientlyemitted as in the case of FIG. 1 as indicated by 15. The light thusemitted has a wavelength corresponding to the energy gap Eg₃₄ of thesemiconductor layer 34.

FIG. 7 illustrates a fourth embodiment of the present invention, inwhich the parts corresponding to those in FIG. 1 are identified by thesame reference numerals and no detailed description will be repeated.This embodiment is identical in construction with the embodiment of FIG.1 except that the non-single-crystal semiconductor layer 4 is made up oftwo i type non-single-crystal semiconductor layers 14A and 14B formedone on the other. In this case, the semiconductors of the layers 14A and14B are the same as that of the layer 14 in FIG. 1 and have differentenergy gaps Eg_(14A) and Eg_(14B) as shown in FIGS. 11A and 11B. As thisembodiment is identical in construction with the embodiment of FIG. 1except the above, the radiative recombination of carriers occurs in thesemiconductor layer 4, i.e. the layers 14A and 14B, emitting lightthough not described in detail. In this case however, the light thusproduced is a combination of lights of different wavelengths because theenergy gaps Eg_(14A) and Eg_(14B) of the semiconductors of the layers14A and 14B are different.

FIGS. 9 and 11 illustrate fifth and sixth embodiments of the presentinvention, which are identical in construction with the embodiment ofFIG. 1 except that the semiconductor layer 4 is formed by the laminationof the i type semiconductor layer 14 described previously in respect ofFIG. 1 and the n type semiconductor layer 24 described previously inrespect of FIG. 3. In this case, however, the energy gaps Eg₁₄ and Eg₂₄of the semiconductors of the layers 14 and 24 may be equal to ordifferent from each other as shown in FIGS. 10A, B and C and FIGS 12A, Band C. In FIG. 9, the layer 14 is shown to be formed on the side of thelayer 3 and, in FIG. 11, it is shown to be formed on the side of thelayer 5.

With the embodiments of FIGS. 9 and 11, the radiative recombination ofcarriers occurs in the semiconductor layers 14 and 24 as is the casewith FIGS. 1 and 3, emitting light though not described in detail. Inthis case, if the energy gaps Eg₁₄ and Eg₂₄ of the semiconductors of thelayers 14 and 24 are different from each other, lights of two differentwavelengths are combined into a composite light.

FIGS. 13 and 15 illustrate seventh and eighth embodiments of the presentinvention, which are identical in construction with the embodiment ofFIG. 1 except that the semiconductor layer 4 is formed by the laminationof the i type semiconductor layer 14 described previously in respect ofFIG. 1 and the p type semiconductor layer 34 described previously inrespect of FIG. 5. In this case, however, the energy gaps EG₁₄ and Eg₃₄of the semiconductors of the layers 14 and 34 may be equal to ordifferent from each other as shown in FIGS. 14A, B and C and FIGS. 16A,B and C. In FIG. 13, the layer 14 is shown to be formed on the side ofthe layer 3 and, in FIG. 15, it is shown to be formed on the side of thelayer 5.

With the embodiments of FIGS. 13 and 15, the radiative recombination ofcarriers occurs in the semiconductor layers 14 and 34 as is the casewith FIGS. 1 and 5, emitting light, though not described in detail. Inthis case, if the energy gaps Eg₁₄ and Eg₃₄ of the semiconductors of thelayers 14 and 34 are different from each other, lights of two differentwavelengths are combined into a composite light.

FIGS. 17 and 19 illustrate ninth and tenth embodiments of the presentinvention, which are identical in construction with the embodiment ofFIG. 1 except that the semiconductor layer 4 is formed by the laminationof the n type semiconductor layer 24 described previously in respect ofFIG. 3 and the p type semiconductor layer 34 described previously inrespect of FIG. 5. In this case, however, the energy gaps Eg₂₄ and Eg₃₄of the semiconductors of the layers 24 and 34 may be equal to ordifferent from each other as shown in FIGS. 18A, B and C and FIGS. 20A,B and C. In FIG. 17, the layer 24 is shown to be formed on the side ofthe layer 3 and, in FIG. 19, it is shown to be formed on the side of thelayer 5.

With the embodiments of FIGS. 17 and 19, the radiative recombination ofcarriers occurs in the semiconductor layers 24 and 34 as is the casewith FIGS. 3 and 5, emitting light though not described in detail. Inthis case, if the energy gaps Eg₂₄ and Eg₃₄ of the semiconductor of thelayers 24 and 34 are different from each other, lights of two differentwavelengths are combined into a composite light.

FIG. 21 illustrates an eleventh embodiment of the present invention inwhich the parts corresponding to those in FIG. 1 are identified by thesame reference numerals and no detailed description will be repeated.This embodiment is identical in construction with the embodiment of FIG.1 except that the non-single-crystal semiconductor layer 4 is made up oftwo n type non-single-crystal semiconductor layers 24A and 24B formedone on the other. In this case, the semiconductors of the layers 24A and24B are the same as that of the layer 24 in FIG. 3 and have differentenergy gaps Eg_(24A) and Eg_(24B) as shown in FIGS. 22A and 22B. As thisembodiment is identical in construction with the embodiment of FIG. 1except the above, the radiative recombination of carriers occurs in thesemiconductor layer 4, i.e. the layers 24A and 24B, emitting light,though not described in detail. In this case, however, the light thusproduced is a combination of lights of different wavelengths because theenergy gaps Eg_(24A) and Eg_(24B) of the semiconductors of the layers24A and 24B are different.

FIG. 23 illustrates a twelfth embodiment of the present invention, inwhich the parts corresponding to those in FIG. 1 are identified by thesame reference numerals and no detailed description will be repeated.This embodiment is identical in construction with the embodiment of FIG.1 except that the non-single-crystal semiconductor layer 4 is made up oftwo p type non-single-crystal semiconductor layers 34A and 34B formedone on the other. In this case, the semiconductor layers of the layers34A and 34B are the same as that of the layer 34 in FIG. 5 and havedifferent energy gaps Eg_(34A) and Eg_(34B) as shown in FIGS. 24A and24B.

As this embodiment is identical in construction with the embodiment ofFIG. 1 except the above, the radiative recombination of carriers occursin the semiconductor layer 4, i.e. the layers 34A and 34B, emittinglight, though not described in detail. In this case, however, the lightthus produced is a combination of lights of different wavelengthsbecause the energy gaps Eg_(34A) and Eg_(34B) of the semiconductors ofthe layers 34A and 34B are different.

FIG. 25 illustrates as thirteenth embodiment of the present invention,in which the parts corresponding to those in FIG. 1, 3 or 5 areidentified by the same reference numerals and no detailed descriptionwill be repeated. This embodiment is identical in construction with theembodiment of FIG. 1, 3 or 5 except that insulating or semi-insulatinglayers 41 and 42, which are thin enough to permit the passagetherethrough of current (as a tunnel current), are sandwiched betweenthe layers 3 and 4 and between the layers 4 and 5, respectively.

The insulating or semi-insulating layers 41 and 42 may be as a siliconnitride. The layer 41 can be formed after the formation of the layer 3and the layer 42 can be formed after the formation of the layer 4.

Since the embodiment of FIG. 25 is identical in construction with theembodiment of FIG. 1, 3 or 5 except that the abovesaid matter, and sincethe insulating or semi-insulating layers 41 and 42 permits the passagetherethrough of current, the same results as those obtainable with theembodiment of FIG. 1, 3 or 5 can be obtained, though not described indetail.

In this case, however, the presence of the insulating or semi-insulatinglayers 41 and 42 clearly defines the surfaces of the layers 3 and 4 onthe side of the layers 4 and 3, respectively, and the surfaces of thelayers 4 and 5 on the sides of layers 5 and 4, respectively. Thisensures to provide excellent characteristics as compared with those inthe case of FIG. 1, 3 or 5.

FIG. 26 illustrates a fourteenth embodiment of the present invention,which is identical in construction with the embodiment of FIG. 7, 9, 11,13, 15, 17, 19, 21 or 23 except that the same insulating orsemi-insulating layers 41 and 42 as those described above in respect ofFIG. 25 are interposed between the layers 3 and 4 and between the layers4 and 5, respectively, in the embodiment of FIG. 7, 9, 11, 13, 15, 17,19, 21 or 23.

As this embodiment is identical in construction with the embodiment ofFIG. 7, 9, 11, 13, 15, 17, 19, 21 or 23 except the above, it is possibleto obtain the same operational effects as those obtainable with such anembodiment and the same feature as described previously in connectionwith FIG. 25.

FIG. 27 illustrates a fifteenth embodiment of the present invention,which is identical in construction with the embodiment of FIG. 1, 3 or 5except the following point. That is to say, non-single-crystalsemiconductor layers 51 and 52 are interposed between the transparentelectrode 2 and the semiconductor layer 3 and between the semiconductorlayer 5 and the electrode 6, respectively. It is preferred that thelayers 51 and 52 be formed of the same semiconductor as those of thelayers 3 and 5. The semiconductors of the layers 51 and 52 are dopedwith the dangling bond and the recombination center neutralizer as isthe case with the layers 3, 4 and 5. The layers 51 and 52 have the sameconductivity type as the layers 3 and 5 respectively and are higher inimpurity concentration than them. It is preferable that the energy gapsof the semiconductors of the layers 51 and 52 be larger than those ofthe layers 3 and 5, respectively.

The exterior surfaces of the layers 3, 4, 5, 51 and 52 are covered withan insulating film 53. The insulating film 53 may be as of asemiconductor oxide such as silicon oxide, a semiconductor nitride suchas silicon nitride or a semiconductor carbide such as silicon carbide.

This embodiment produces the same effects as those obtainable with theembodiment of FIG. 1, 3 or 5, though not described in detail, becausethis embodiment is identical in construction with the embodiment of FIG.1, 3 or 5 except the abovesaid matter.

In this case, the layers 51 and 52 make excellent ohmic contact with theelectrodes 2 and 6, respectively, as compared with the ohmic contact ofthe layers 3 and 5 with electrodes 2 and 6. Accordingly, the layers 3and 5 are electrically connected to the electrodes 2 and 6,respectively, with certainty. Further, the insulating layer 53 protectsthe layers 3, 4, 5, 51 and 52 and prevents leakage current between thejunctions between the layers 3 and 4 and between the layers 4 and 5 dueto contamination. In addition, the insulating layer 53 can be used as alight reflecting film, too. Therefore, this embodiment exhibitsexcellent characteristics as compared with the embodiment of FIG. 1, 3,or 5.

FIG. 28 illustrates a sixteenth embodiment of the present invention,which is identical in construction with the embodiment of FIG. 7, 9, 11,13, 15, 17, 19, 21 or 23 except that the same semiconductor layers 51and 52 as those in FIG. 27 are sandwiched between the electrode 2 andthe semiconductor layer 3 and between the semiconductor layer 5 and theelectrode 6, respectively, as in the case of FIG. 27, and that theexterior surfaces of the semiconductor layers 3, 4, 5, 51 and 52 arecovered with the insulating film 53.

Accordingly, this embodiment, though not described in detail, possessesthe same operational effects as those obtainable with the embodiment ofFIG. 7, 9, 11, 13, 15, 17, 19, 21 or 23 and the same feature as thatdescribed above in respect of FIG. 27.

FIG. 29 and 30 respectively illustrate seventeenth and eighteenthembodiments of the present invention, in which the parts correspondingto those in FIGS. 27 and 28 are identified by the same referencenumerals and no detailed description will be repeated. These embodimentsare identical in construction with the embodiments of FIGS. 27 and 28except that the insulating or semi-insulating layers 41 and 42 areinterposed between the layers 3 and 4 and between the layers 4 and 5,respectively, as in the cases of FIGS. 25 and 26.

Therefore, these embodiments, though not described in detail, possessthe same excellent characteristics as those described above with regardto FIGS. 27 and 28 and the same excellent features as those describedpreviously in respect of FIGS. 25 and 26.

FIG. 31 illustrates a nineteenth embodiment of the present invention, inwhich the parts corresponding to those in FIG. 1 are identified by thesame reference numerals and no detailed description will be repeated.This embodiment is identical in construction with the embodiment of FIG.1 except in the following point: In FIG. 1, the non-single-crystalsemiconductor layer 4 is constituted by the i type semiconductor layer14 and the layer 14 extends all over the p type layer 3, so that the ntype layer 5 is formed on the layer 4 without making contact with thelayer 3. In this embodiment, however, many layers similar to the layer 4are formed on the layer 3 as indicated by 4' and consequently the layer5 is formed on the layer 3 as indicated by 4' and consequently the layer5 is formed on the layer 3 in such a manner that the layers 4' areburied in the layer 5. In this case, the layers 4' are constituted byone group of i type semiconductor layers 14' similar to the layer 14.Each of the layers 14' forms a pi junction 8' between it and the layer 3and an ni junction 9' between it and the layer 5 as is the case with thelayer 14. The semiconductor layer 5 makes direct contact with thesemiconductor layer 3 at those areas where the layers 4' are not formed;accordingly, many pn junctions 60 are formed between the semiconductorlayers 3 and 5.

The light emitting semiconductor device of FIG. 31 has such aconstruction that the many pin junction structures by the semiconductorlayers 3, 14' and 5 and the many pn junction structures by thesemiconductor layers 3 and 5 are arranged side by side. Connectingacross the electrodes 2 and 6 the bias power source 11 which is forwardwith respect to the pin junction structures and the pn junctionstructures, radiative recombination of carriers tends to occur in thesemiconductor layer 14' in the pin junction structure as in the case ofFIG. 1 and radiative recombination of carriers tends to occur in thesemiconductor layer 3 or 5 in the vicinity of the pn junction 60 as inthe case of an ordinary pn junction structure. In the case of the pinjunction structures, however, the semiconductor of the semiconductorlayer 14 has a smaller energy gap than does the semiconductor of thesemiconductor layer 3 or 5 and at least holes or electrons are apt to beaccumulated in the semiconductor layer 14', so that the carrierrecombination in the semiconductor layer 14' of the pin junctionstructure readily occurs as compared with the carrier recombination inthe semiconductor layer 3 or 5 of the pn junction structure in thevicinity of the pn junction 60. Once the carrier recombination has beencaused in the semiconductor layer 14' of the pin junction structure,carriers in the semiconductor layer 3 or 5 of the pn junction structurein the vicinity of the pn junction 60 flow into the semiconductor layer14' of the pin junction structure in such a manner as to make up forcarriers in the semiconductor layer 14' of the pin junction. As a resultof this, radiative recombination of carriers occurs mainly in thesemiconductor layer 14' of the pin junction structure, emitting lightfrom the semiconductor layer 4' as in the case of FIG. 1.

FIG. 32 illustrates a twentieth embodiment of the light emittingsemiconductor device of the present invention, in which the partscorresponding to those in FIG. 31 are identified by the same referencenumerals and no detailed description will be repeated. This embodimentis identical in construction with the embodiment of FIG. 31 except thatthe i type layer 14' forming each of the semiconductor layers 4' and thelatter is replaced with the same n type layer 24' as that 24 employed inthe embodiment of FIG. 3. Accordingly, many pn junctions 28' are formedbetween the semiconductor layer 3 and the many semiconductor layers 24'and many nn junctions 29' are formed between the many semiconductorlayers 24' and the semiconductor layer 5. Further, as in the case ofFIG. 32, many pn junctions 60 are formed between the semiconductorlayers 3 and 5, as in the case of FIG. 31.

In the light emitting semiconductor device of FIG. 32, many pn junctionstructures by the semiconductor layers 3, 24' and 5 and many pn junctionstructures by the semiconductor layers 3 and 5 are arranged side byside. Connecting across the electrodes 2 and 6 the bias power source 11which is forward with respect to the pn junction structures, radiativerecombination of carriers tends to occur in the semiconductor layer 24'in the pn junction structure by the semiconductor layers 3, 24' and 5 asin the case of FIG. 31, and radiative recombination of carriers tends tooccur, as in the case of an ordinary pn junction structure, in thesemiconductor layer 3 or 5 in the pn junction structure by thesemiconductor layers 3 and 5 in the vicinity of the pn junction 60. Butin the case of the pn junction structure by the semiconductor layers 3,24' and 5, since the semiconductor of the layer 24' has a smaller energygap than does the semiconductor of the layer 3 or 5 as in the case ofFIG. 31, the carrier recombination readily occurs as compared with thatin the pn junction structure by the semiconductor layers 3 and 5. Oncethe carrier recombination has been caused in the semiconductor layer 24'of the pn junction structure by the semiconductor layers 3, 24' and 5,carriers in the pn junction structure by the semiconductor layers 3 and5 flow out therefrom into the semiconductor layer 24'. In consequence,radiative recombination of carriers occur mainly in the semiconductorlayer 24', emitting therefrom light.

FIG. 33 illustrates a twenty-first embodiment of the light emittingsemiconductor device of the present invention, in which the partscorresponding to those in FIG. 31 are identified by the same referencenumerals and no detailed description will be repeated. This embodimentis identical in construction with the embodiment of FIG. 31 except thatthe I type layer 14' forming each of the semiconductor layers 4' in thelatter is replaced with the same p type layer 34' as that 34 employed inthe embodiment of FIG. 5. Accordingly, many pp junctions 38' are formedbetween the semiconductor layer 3 and the many semiconductor layers 34'and many pn junctions 39' are formed between the many semiconductorlayers 34' and the semiconductor layer 5. Further, as in the case ofFIG. 33, many pn junctions 60 are formed between the semiconductorlayers 3 and 5, as in the case of FIG. 31.

In the light emitting semiconductor device of FIG. 33, many pn junctionstructures by the semiconductor layers 3, 34' and 5 and many pn junctionstructures by the semiconductor layers 3 and 5 are arranged side byside. Connecting across the electrodes 2 and 6 the bias power source 11which is forward with respect to the pn junction structures, radiativerecombination of carriers occurs mainly in the semiconductor layer 34'to emit therefrom light as in the case of FIG. 31, though not describedin detail.

FIG. 34 illustrates a twenty-second embodiment of the present invention,in which the parts corresponding to those in FIG. 31 are identified bythe same reference numerals. This embodiment is identical inconstruction with the embodiment of FIG. 31 except that the layer 4' isformed by a first combination of a first group of i type semiconductorlayers 14A' similar to those 14' referred to previously in respect ofFIG. 31 and a second group of i type semiconductor layers 14B' similarto those 14' but different in energy gap from the layers 14A', a secondcombination of a first group of the i type semiconductor layer 14' and asecond group of the n type semiconductors layers 24' describedpreviously in connection with FIG. 32, a third combination of a firstgroup of the i type semiconductor layers 14' and a second group of the ptype semiconductor layers 34' mentioned previously with respect to FIG.33, a fourth combination of a first group of the n type semiconductorlayers 24' and a second group of the p type semiconductor layers 34', afifth combination of a first group of n type semiconductor layers 24A'similar to those 24' and a second group of n type semiconductor layers24B' similar to those 24', or a sixth combination of a first group of ptype semiconductor layers 34A' similar to those 34' and a second groupof p type semiconductor layers 34B' similar to those 34'. FIG. 34 showsfor the sake of simplicity, the case of the abovesaid first combination.In the cases of the first, fifth and sixth combinations, thesemiconductors of the first and second groups have different energygaps. In the cases of the second, third and fourth combinations, it doesnot matter whether the semiconductors of the first and second groupshave the same energy gap or not.

With the embodiment of FIG. 34 which has the abovesaid arrangement,though not described in detail, it is possible to obtain the sameoperational effects as in the embodiments of FIGS. 31 to 33 and theexcellent features referred to previously in respect of FIGS. 7, 9, 11,13, 15, 17, 19, 21 or 23.

FIG. 35 illustrates a twenty-third embodiment of the present invention,in which the parts corresponding to those in FIG. 1 are identified bythe same reference numerals, and no detailed description will berepeated. This embodiment is identical in construction with theembodiment of FIG. 1 except in the following point.

On the layer 3 is formed the same i type layer 14 as in the case of FIG.1, the same n type layer 24 as in the case of FIG. 3 or the same p typelayer 34 as in the case of FIG. 5. Further, there are formed on thelayer 14, 24 or 34 many semiconductor layers 4' similar to those used inFIGS. 31, 32 or 33. On the layer 14, 24 or 34 is formed the layer 5 in amanner to bury therein the layers 4'.

In this embodiment, since its construction is a combination of theembodiment of FIGS. 1, 3 or 5 and the embodiment of FIGS. 31, 32 or 33,it is possible to obtain the same effects as those obtainable with theembodiments of FIGS. 1, 3 or 5 and FIGS. 31, 32 or 33, though notdescribed in detail.

FIG. 36 illustrates a twenty-fourth embodiment of the present invention,in which the parts corresponding to those in FIG. 1 are identified bythe same reference numerals, and no detailed description will berepeated.

On the layer 3 are formed many semiconductor layers 4' similar to thoseused in FIGS. 31, 32 or 33. The layer 3 is covered with the same i type,n type or p type layer 14, 24 or 34 as that in FIGS. 1, 3 or 5 to burytherein the layers 4. The layer 5 is formed on the layer 14, 24 or 34.

This embodiment is constructed by a combination of the embodiment ofFIGS. 1, 3 or 5 and the embodiment of FIG. 31, 32 or 33, and hence itproduces the same effects as those in the case of FIG. 35.

FIGS. 37 and 38 illustrate twenty-fifth and twenty-sixth embodiments ofthe present invention, in which the parts corresponding to those inFIGS. 35 and 36 are marked with the same reference numerals. Theseembodiments are identical in construction with the embodiments of FIGS.35 and 36, respectively, except that the layer 4' is formed by the samefirst, second, third, fourth, fifth or sixth combination as in the caseof FIG. 34.

With these embodiments, it is possible to obtain the same operationaleffects as those in the cases of FIGS. 35 and 36 and the sameoperational effect as that in the case FIG. 34, though not described indetail.

FIGS. 39A to 39C illustrate a twenty-seventh embodiment of the presentinvention, in which the parts corresponding to those in FIG. 27 areidentified by the same reference numerals. This embodiment has thearrangement that a plurality of such light emitting semiconductordevices U as described previously in respect of FIG. 27 are arranged ina matrix form. In this case, the devices U are formed on the samesubstrate 1 and are covered with an insulating layer 70. The electrodes2 of the device U arranged on each column line are replaced with columnselecting, transparent stripe-like conductor layers 71 and theelectrodes 6 of the devices U arranged on each row line are connectedwith row selecting, stripe-like conductor layers 72, on the insulatinglayer 70 through windows 73 formed therein.

This embodiment electrically constitutes a matrix circuit shown in FIG.40, though not described in detail. Accordingly, it is possible toprovide a display of a picture by suitably selecting the columnselecting conductor layers 71 and the row selecting conductor layers 72.

FIGS. 41A to 41C illustrate a twenty-eighth embodiment of the presentinvention, which is identical in construction with the embodiment ofFIGS. 39A to 39C except that the semiconductor layers 3, 4, 5, 51 and 52of the devices U arranged on each row line are coupled together. Alsothis embodiment has the same operational effect as that obtainable withthe embodiment of FIGS. 39A to 39C, though not described in detail.

FIGS. 42A to 42C illustrate a twenty-ninth embodiment of the presentinvention, which is identical in construction with the embodiment ofFIGS. 39A to 39C except that the semiconductor layers 3, 4, 5, 51 and 52of the devices U arranged on each column line are coupled together. Alsothis embodiment has the same operational effect as that obtainable withthe embodiment of FIGS. 39A to 39C, though not described in detail.

FIGS. 43A to 43C illustrate a thirtieth embodiment of the presentinvention, which is identical in construction with the embodiment ofFIGS. 39A to 39C except that the semiconductor layers 3, 4, 5, 51 and 52of all the devices U are coupled together. Also this embodiment has thesame operational effect as those obtainable with the embodiment of FIGS.39A to 39C, though not described in detail.

The foregoing description has been given some embodiments of the presentinvention. In the first to eighteenth embodiments it is also possible todope the non-single-crystal semiconductor layer 4 with an impurity whichforms the radiative carrier recombination centers, such as iron, gold orthe like, thereby emitting light by virtue of the impurity level. Alsoin the nineteenth to twenty-second embodiments the semiconductor layer4' can similarly be doped with an impurity that forms the radiativerecombination centers.

Moreover, in the twenty-third to twenty-sixth embodiments thesemiconductor layers 14, 24, 34 and 4' can each be doped with animpurity which forms the radiative recombination centers.

In the thirteenth and fourteenth embodiments of FIGS. 25 and 26 it isalso possible to omit either one of the insulating or semi-insulatinglayers 41 and 42. In the first to fourteenth embodiments it is alsopossible to provide the insulating layer 53 as in the fifteenth andsixteenth embodiments of FIGS. 27 and 28. Furthermore, the same matrixstructure as in the cases of FIGS. 39 to 43 can also be obtained usingthe light emitting semiconductor devices of the first to fourteenth andsixteenth to twenty-sixth embodiments.

It is also possible to make the transparent substrate 1 and thetransparent electrode 2 opaque and the electrode 6 transparent foremitting light from the side of this electrode. Also it is possible toomit the electrode 2 and the make the substrate 1 conductive to cause itto serve as the electrode.

What is claimed is:
 1. A light emitting semiconductor devicecomprising:a transparent glass substrate; a plurality of light emittingelements consisting of non-single-crystalline semiconductor which are inthe form of a matrix; an insulator disposed between and in directcontact with the side surfaces of said light emitting elements and withwhich the spaces between said elements are completely filled; and aplurality of column electrode lines and a plurality of row electrodelines for addressing particular elements and causing light emission fromsaid particular elements through said transparent glass substrate. 2.The device of claim 1 wherein side and upper surfaces of said lightemitting elements are embedded in said insulator which extends on thesaid side and upper surfaces of said light emitting elements.
 3. Thedevice of claim 1 wherein upper and lower surfaces of said insulator areflat, said column or row lines extending over said flat surfaces.
 4. Thedevice of claim 1 where said insulator is an organic resin layer.
 5. Alight emitting semiconductor device of claim 1, wherein the lightemitting elements comprise a first non-single crystalline semiconductorlayer of a first conductivity type, a second non-single crystallinesemiconductor layer formed on the first non-single crystallinesemiconductor layer, and a third non-single crystalline semiconductorlayer of a second conductivity type opposite to the first conductivitytype, said third non-single crystalline semiconductor layer being formedon the second non-single crystalline semiconductor layer.
 6. A lightemitting semiconductor device of claim 5, wherein the second non-singlecrystalline semiconductor layer has a smaller energy band gap than thefirst and third non-single crystalline semiconductor layers.
 7. A lightemitting semiconductor device of claim 5, wherein a band gap of thesecond non-single crystalline semiconductor layer is equal to a band gapof the first non-single crystalline semiconductor layer and smaller thana bank gap of the third non-single crystalline semiconductor layer.
 8. Alight emitting semiconductor device of claim 5, wherein a band gap ofthe second non-single crystalline semiconductor layer is equal to a bandgap of the third non-single crystalline semiconductor layer and smallerthan a band gap of the first non-single crystalline semiconductor layer.9. A light emitting semiconductor device of claim 1, wherein the lightemitting elements comprise a first non-single crystalline semiconductorlayer of a first conductivity type, a second and third non-singlecrystalline semiconductor layer formed on the first non-singlecrystalline semiconductor layer, and a fourth non-single crystallinesemiconductor layer of a second conductivity type opposite to the firstconductivity type that is formed on the third non-single crystallinesemiconductor layer, wherein the second and third non-single crystallinesemiconductor layers have smaller band gaps than the first and fourthnon-single crystalline semiconductor semiconductor layers.